House Speaker John A. Boehner announces a House panel to initiate steps on behalf of the Defense of Marriage Act.

Reporting from Washington — House Speaker John A. Boehner brought the Republican-led House into the gay marriage debate Friday by announcing plans to initiate a legal defense of the 1996 law that bars the federal government from giving legal rights or federal benefits to gay couples.

Boehner, an Ohio Republican, seized on the opportunity to take up a social issue after the Obama administration announced last week that its Justice Department would no longer defend the law. The administration concluded that the law, known as the Defense of Marriage Act, was unconstitutional.

If a Republican-dominated House panel agrees to appoint one or more lawyers, as is expected, the GOP would keep alive several pending cases brought on behalf of legally married gay Americans that would otherwise have come to a quiet close.

"The constitutionality of this law should be determined by the courts — not by the president unilaterally — and this action by the House will ensure the matter is addressed in a manner consistent with our Constitution," Boehner said.

Advocates of gay rights and their allies in Congress characterized the GOP decision as out of touch with Americans' changing views on same-sex marriage.

The Defense of Marriage Act was passed by a Republican majority in Congress 15 years ago, and signed into law by President Clinton. It was largely designed to prevent same-sex marriages authorized in one state from being legally recognized nationwide, as is done routinely with heterosexual marriages.

The administration's decision not to defend the law in cases pending in Connecticut, Massachusetts and New York provided an opening for congressional Republicans to take greater ownership of an issue that is important to their conservative base.

Family Research Council President Tony Perkins thanked Boehner for protecting "the institution of marriage."

Yet, in deciding to convene a five-member House panel to initiate the defense, Boehner risks alienating voters who are more interested in seeing Congress engage in debate on fiscal issues rather than hot-button social topics.

"Not only are they detracting from their agenda of jobs, jobs, jobs; they are taking a case that has a high propensity of failure," said Fred Sainz, a vice president at the Human Rights Coalition.

Five states and the District of Columbia authorize gay marriages, and the administration's action does not affect the many states that do not. The administration also said it would continue to enforce the law — including its denial of spousal benefits — until the courts rule it unconstitutional.